Transferring data between DRAM and SRAM

ABSTRACT

Methods and devices related to transferring data between DRAM and SRAM. One method includes activating a first portion of a dynamic random access memory (DRAM), reading data from the first portion of the DRAM, latching the data from the first portion of the DRAM in one or more sense amplifiers, and writing the data from the one or more sense amplifiers to a first portion of a static random access memory (SRAM).

PRIORITY INFORMATION

This application is a Continuation of U.S. application Ser. No.17/124,697, filed Dec. 17, 2020, the contents of which are includedherein by reference.

TECHNICAL FIELD

The present disclosure relates generally to semiconductor memory andmethods, and more particularly, to apparatuses and methods related totransferring data between DRAM and SRAM.

BACKGROUND

Memory devices are typically provided as internal, semiconductor,integrated circuits in computers or other electronic devices. There aremany different types of memory including volatile and non-volatilememory. Volatile memory can require power to maintain its data andincludes random-access memory (RAM), static random access memory (SRAM),dynamic random access memory (DRAM), and synchronous dynamic randomaccess memory (SDRAM), among others. Non-volatile memory can providepersistent data by retaining stored data when not powered and caninclude NAND flash memory, NOR flash memory, read only memory (ROM),Electrically Erasable Programmable ROM (EEPROM), Erasable ProgrammableROM (EPROM), and resistance variable memory such as phase change randomaccess memory (PCRAM), 3D XPoint™, resistive random access memory(RRAM), and magnetoresistive random access memory (MRAM), among others.

Memory is also utilized as volatile and non-volatile data storage for awide range of electronic applications, including, but not limited topersonal computers, portable memory sticks, digital cameras, cellulartelephones, portable music players such as MP3 players, movie players,and other electronic devices. Memory cells can be arranged into arrays,with the arrays being used in memory devices.

Computers or other electronic devices can include a number of memorydevices. In some examples, different types of memory can be included onthe same electronic device for optimal performance of the electronicdevice. However, different types of memory devices may require separatedata paths and/or controls for each type of memory device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram of a system for transferring data betweenDRAM and SRAM in accordance with a number of embodiments of the presentdisclosure.

FIG. 1B is a block diagram of an apparatus for transferring data betweenDRAM and SRAM in accordance with a number of embodiments of the presentdisclosure.

FIG. 2 is a schematic diagram illustrating circuitry for a plurality ofshared I/O lines in a data path of an array in accordance with a numberof embodiments of the present disclosure.

FIG. 3A is a timing diagram illustrating transferring data from DRAM toSRAM in accordance with a number of embodiments of the presentdisclosure.

FIG. 3B is a schematic diagram illustrating circuitry for transferringdata from DRAM to SRAM in accordance with a number of embodiments of thepresent disclosure.

FIG. 4A is a timing diagram illustrating transferring data from SRAM toDRAM in accordance with a number of embodiments of the presentdisclosure.

FIG. 4B is a schematic diagram illustrating circuitry for transferringdata from SRAM to DRAM in accordance with a number of embodiments of thepresent disclosure.

FIG. 5 is a flow diagram of a method for transferring data from DRAM toSRAM in accordance with a number of embodiments of the presentdisclosure.

DETAILED DESCRIPTION

The present disclosure includes methods and apparatuses related totransferring data between DRAM and SRAM. An example method includesactivating a first portion of a DRAM, reading data from the firstportion of the DRAM, latching the data from the first portion of theDRAM in one or more sense amplifiers, and writing the data from the oneor more sense amplifiers to a first portion of a SRAM.

In some examples, data can be transferred between the DRAM and the SRAMusing a DRAM data path. For example, data can be transferred from thefirst portion of the DRAM to the one or more sense amplifiers via afirst data path and the data can be transferred from the one or moresense amplifiers to the first portion of the SRAM via the same firstdata path. Similarly, data can be transferred from a first portion ofthe SRAM to the one or more sense amplifiers via the first data path andthe data can be transferred from the one or more sense amplifiers to thefirst portion of the DRAM via the same first data path.

In a number of embodiments, data can be transferring between the DRAMand the SRAM using DRAM controls. For example, the SRAM can receive aDRAM command and in response data can be written from the one or moresense amplifiers to the first portion of the SRAM. The SRAM can alsoreceive a different DRAM command and in response read the data from theSRAM.

Using a DRAM data path and/or DRAM controls to transfer data betweenDRAM and SRAM can reduce the number of data paths and/or circuitry on amemory device, reduce the overall size of the memory device, and/or freeup space on the memory device for additional memory resources,processing resources, and/or circuitry.

As used herein, “a number of” something can refer to one or more of suchthings. For example, a number of memory devices can refer to one or morememory devices. A “plurality” of something intends two or more.Additionally, designators such as “U”, “V”, “W”, “X”, “Y”, and “Z”, asused herein, particularly with respect to reference numerals in thedrawings, indicates that a number of the particular feature sodesignated can be included with a number of embodiments of the presentdisclosure.

The figures herein follow a numbering convention in which the firstdigit or digits correspond to the drawing figure number and theremaining digits identify an element or component in the drawing.Similar elements or components between different figures may beidentified by the use of similar digits. For example, reference numeral323 may reference element “23” in FIG. 3A, and a similar element may bereferenced as 423 in FIG. 4A. In some instances, a plurality of similar,but functionally and/or structurally distinguishable, elements orcomponents in the same figure or in different figures may be referencedsequentially with the same element number (e.g., 118-1, 118-2, 118-3,118-4, 118-5, 118-6, 118-7, and 118-X in FIG. 1 ). As will beappreciated, elements shown in the various embodiments herein can beadded, exchanged, and/or eliminated so as to provide a number ofadditional embodiments of the present disclosure. In addition, theproportion and the relative scale of the elements provided in thefigures are intended to illustrate various embodiments of the presentdisclosure and are not to be used in a limiting sense.

FIG. 1A is a block diagram of a system for writing data between DRAM andSRAM in accordance with a number of embodiments of the presentdisclosure. The system 100 can be a system in the form of a computersystem, for example. The system 100 can include a host 102 and a memorydevice 106.

The host 102 can be coupled to or in communication with the memorydevice 106. The host 102 can include a host controller 104. Commands canbe sent to the memory device 106 from the host controller 104. Forexample, the host controller 104 can send a command to read and/or writedata from the memory device 106.

The memory device 106 can include a controller 108 and a memory array110. The memory array 110 can be volatile memory. For example, thememory array 110 can be DRAM. The controller 108 can include aprocessing resource 112 and control circuitry 113. The processingresource 112 can be coupled to the control circuitry 113. In someexamples, the processing resource 112 can be a RISC-V processor. Theprocessing resource 112 can include a cache 114. The cache 114 can beSRAM. In some examples, the cache 114 can include two ports and amultiplexer (mux) 116. The mux 116 can allow the cache 114 to switchbetween the two ports. For example, the cache 114 can be coupled to thehost 102 when a first port is selected by the mux 116 and the cache 114can be coupled to the memory array 110 when a second port is selected bythe mux 116.

FIG. 1B is a block diagram of an apparatus for writing data between DRAMand SRAM in accordance with a number of embodiments of the presentdisclosure. The apparatus can be, for example, memory device 106. Theapparatus can include controller 108 and memory array 110, as describedin FIG. 1A.

The memory array 110 can include a number of memory banks 118-1, . . . ,118-X. In some examples the number of memory banks 118-1, . . . , 118-Xcan be DRAM memory banks. The controller 108 can be coupled to each ofthe number of memory banks 118-1, . . . , 118-X via data bus 119. Readand/or write data commands can be sent via data bus 119 from thecontroller 108 to one or more of the number of memory banks 118-1, . . ., 118-X and one or more of the number of memory banks 118-1, . . . ,118-X can transmit data to the controller 108 via the data bus 119.

FIG. 2 is a schematic diagram illustrating circuitry for data movementin a memory device in accordance with a number of embodiments of thepresent disclosure. FIG. 2 shows eight sense amplifiers (e.g., senseamplifiers 0, 1, . . . , 7 shown at 220-0, 220-1, . . . , 220-7,respectively) each coupled to a respective pair of complementary sharedI/O lines 222 (e.g., shared I/O line and shared I/O line*). FIG. 2 alsoshows eight compute components (e.g., compute components 0, 1, . . . , 7shown at 224-0, 224-1, . . . , 224-7) each coupled to a respective senseamplifier (e.g., as shown for sense amplifier 0 at 220-0) via respectivepass gates 226-1 and 226-2 and digit lines 228-1 and 228-2. The passgates can be connected and can be controlled by an operation selectionsignal, Pass. For example, an output of the selection logic can becoupled to the gates of the pass gates 226-1 and 226-2 and digit lines228-1 and 228-2. Corresponding pairs of the sense amplifiers and computecomponents can contribute to formation of the sensing circuitryindicated at 230-0, 230-1, . . . , 230-7.

Data values present on the pair of complementary digit lines 228-1 and228-2 can be loaded into the compute component 224-0. For example, whenthe pass gates 226-1 and 226-2 are enabled, data values on the pair ofcomplementary digit lines 228-1 and 228-2 can be passed from the senseamplifiers to the compute component (e.g., 220-0 to 224-0). The datavalues on the pair of complementary digit lines 228-1 and 228-2 can bethe data value stored in the sense amplifier 220-0 when the senseamplifier is fired.

A combination of one sense amplifier with one compute component cancontribute to the sensing circuitry (e.g., 230-0, 230-1, . . . , 230-7)of a portion of a DRAM memory subarray 221 coupled to a shared I/O line222 shared by a number of logic stripes in a data path of the shared I/Olines 222.

The configurations of embodiments illustrated in FIG. 2 are shown forpurposes of clarity and are not limited to these configurations. Forinstance, the configuration illustrated in FIG. 2 for the senseamplifiers 220-0, 220-1, . . . , 220-7 in combination with the computecomponents 224-0, 224-1, . . . , 224-7 and the shared I/O line 222 isnot limited to half the combination of the sense amplifiers 220-0,220-1, . . . , 220-7 with the compute components 224-0, 224-1, . . . ,224-7 of the sensing circuitry being formed above the columns 234 ofmemory cells (not shown) and half being formed below the columns 234 ofmemory cells. Nor are the number of such combinations of the senseamplifiers with the compute components forming the sensing circuitryconfigured to couple to a shared I/O line limited to eight. In addition,the configuration of the shared I/O line 222 is not limited to beingsplit into two for separately coupling each of the two sets ofcomplementary digit lines 228-1 and 228-2, nor is the positioning of theshared I/O line 222 limited to being in the middle of the combination ofthe sense amplifiers and the compute components forming the sensingcircuitry (e.g., rather than being at either end of the combination ofthe sense amplifiers and the compute components).

The circuitry illustrated in FIG. 2 also shows column select circuitry236-1 and 236-2 that is configured to implement data movement operationswith respect to particular columns 234 of a subarray 221, thecomplementary digit lines 228-1 and 228-2 associated therewith, and theshared I/O line 222 (e.g., as directed by the controller 108 shown inFIGS. 1A-1B). For example, column select circuitry 236-1 has selectlines 0, 2, 4, and 6 that are configured to couple with correspondingcolumns, such as column 0 (234-0), column 2, column 4, and column 6.Column select circuitry 236-2 has select lines 1, 3, 5, and 7 that areconfigured to couple with corresponding columns, such as column 1,column 3, column 5, and column 7. The column select circuitry 236described in connection with FIG. 2 can, in various embodiments,represent at least a portion of the functionality embodied by andcontained in multiplexers, e.g., an eight (8) way multiplexer, sixteen(16) way multiplexer, etc.

Controller (e.g., controller 108 in FIGS. 1A and 1B) can be coupled tocolumn select circuitry 236 to control select lines (e.g., select line0) to access data values stored in the sense amplifiers, computecomponents, and/or present on the pair of complementary digit lines(e.g., 228-1 and 228-2 when selection transistors 238-1 and 238-2 areactivated via signals from select line 0). Activating the selectiontransistors 238-1 and 238-2 (e.g., as directed by the controller 108)enables coupling of sense amplifier 220-0, compute component 224-0,and/or complementary digit lines 228-1 and 228-2 of column 0 (234-0) tomove data values on digit line 0 and digit line 0* to shared I/O line222. For example, the moved data values may be data values from aparticular row 240 stored (cached) in sense amplifier 220-0 and/orcompute component 224-0. Data values from each of columns 0 through 7can similarly be selected by controller 108 activating the appropriateselection transistors.

Moreover, enabling (e.g., activating) the selection transistors (e.g.,selection transistors 238-1 and 238-2) can enable a particular senseamplifier and/or compute component (e.g., 220-0 and/or 224-0,respectively) to be coupled with a shared I/O line 222 such that datavalues stored by an amplifier and/or compute component can be moved to(e.g., placed on and/or transferred to) the shared I/O line 222. In someembodiments, one column at a time is selected (e.g., column 234-0) to becoupled to a particular shared I/O line 222 to move (e.g., copy,transfer, and/or transport) the stored data values. The shared I/O line222 can be part of the data path (e.g., data path 323 in FIG. 3B anddata path 423 in FIG. 4B) that transfers data between DRAM in SRAM. Inthe example configuration of FIG. 2 , the shared I/O line 222 isillustrated as a shared, differential I/O line pair (e.g., shared I/Oline and shared I/O line*). Hence, selection of column 0 (234-0) couldyield two data values (e.g., two bits with values of 0 and/or 1) from arow (e.g., row 240) and/or as stored in the sense amplifier and/orcompute component associated with complementary digit lines 228-1 and228-2. These data values could be input in parallel to each shared,differential I/O pair (e.g., shared I/O and shared I/O*) of the shareddifferential I/O line 222.

FIG. 3A is a timing diagram illustrating writing data from DRAM to SRAMin accordance with a number of embodiments of the present disclosure.The DRAM can execute a number of commands including activating rowsand/or banks 341, reading data 342, writing data 343, selecting a row344, selecting a column 345, and selecting a Bank 346. The SRAM can alsoexecute a number of commands including selecting a row 380, selecting acolumn 381, reading data 382, and writing data 383.

The process of transferring data from DRAM to SRAM can start at time348-0 and the data can be transferred via data line (e.g., data path)347. The time can be tracked by clock cycles 384. At time 348-1, atarget bank and/or row of DRAM can be activated. A first column of datacan be read from the row of DRAM at time 348-2. At time 348-3, the firstcolumn of data from the row of DRAM can be transferred to a target rowin SRAM. A second column of data can be read from the row of DRAM attime 348-4. At time 348-5, the second column of data from the row ofDRAM can be transferred to the target row in SRAM. A third column ofdata can be read from the row of DRAM at 348-6. At time 348-7, the thirdcolumn of data from the row of DRAM can be transferred to the target rowof SRAM. A fourth column of data can be read from the row of DRAM at348-8. At time 348-9, the fourth column of data from the row of DRAM canbe transferred to the target row of SRAM.

FIG. 3B is a schematic diagram illustrating circuitry for transferringdata from DRAM to SRAM in accordance with a number of embodiments of thepresent disclosure. The FIG. 3B schematic diagram can include a memoryarray 310 coupled to a cache 314 via data line (e.g., data path) 323.For ease of explanation and illustration of FIG. 3B, the memory array310 can be DRAM 310 and the cache 314 can be SRAM 314. The data path fortransferring data between DRAM and SRAM can include digit lines thattransfer data from memory cells at intersections of rows and columns tosense amplifiers 306-0, . . . , 306-Y. The data path for transferringdata between DRAM and SRAM can include data line 323 that can be coupledto sense amplifiers sense amplifiers 306-0, . . . , 306-Y. Data line 323can also be coupled to a shared I/O line (e.g., shared I/O line 222) totransfer data between DRAM and SRAM. The data path can also include dataline 323 can be coupled to and/or be part of data line 347. Data lines323 and 347 can be coupled to the DRAM interface and SRAM interface,which can receive data and/or commands on data lines 323 and 347 andtransfer the data and/or commands to components of the DRAM and SRAM.

The DRAM 310 can include a number of rows 340-0, . . . , 340-W and anumber of columns 334-0, . . . , 334-Z and the SRAM 314 can include anumber of rows 350-0, . . . , 350-U and a number of columns 354-0, . . ., 354-V. The DRAM 310 can also include a number of sense amplifiers306-0, . . . , 306-Y. Memory cells can be located at the intersectionsof rows 340-0, . . . , 340-W and columns 334-0, . . . , 334-Z and at theintersections of rows 350-0, . . . , 350-U and columns 354-0, . . . ,354-V.

To transfer data from the DRAM 310 to the SRAM 314, one of the number ofrows 340-0, . . . , 340-W of DRAM 310 can be activated, data from amemory cell coupled to one of the number of columns 334-0, . . . , 334-Zin DRAM 310 can be read and latched in one of the number of senseamplifiers 306-0, . . . , 306-Y, one of the number of rows 350-0, . . ., 350-U in SRAM 314 can be selected, and the data can be transferred toone of the number of columns 354-0, . . . , 354-V in SRAM 314. Forexample, row 340-0 can be activated, data from column 334-0 can be readand latched in sense amplifier 306-0, the data can be transmitted to theSRAM via data line 323, row 350-0 can be selected, and the data can betransferred to column 354-0 in the SRAM 314. Once a row is activated,data can be transferred column by column by activating columns one byone. Transferring the data can include transferring data to and/or froma memory cell coupled to the activated row and column, and repeating theprocess by activating additional columns of the activated row (e.g.,activating and transferring data to and/or from a first column, then asecond column, then a third column, etc.).

FIG. 4A is a timing diagram illustrating transferring data from SRAM toDRAM in accordance with a number of embodiments of the presentdisclosure. As described in FIG. 3A, the DRAM can execute a number ofcommands including activating rows and/or banks 441, reading data 442,writing data 443, selecting a row 444, selecting a column 445, andselecting a Bank 446. The SRAM can also execute a number of commandsincluding selecting a row 480, selecting a column 481, reading data 482,and writing data 483.

The process of transferring data from SRAM to DRAM can start at time360-0 and the data can be transferred via data line (e.g., data path)447. The time can be tracked by clock cycles 484. At time 460-1, atarget bank and/or row of DRAM can be activated. A first column of datacan be read from SRAM at time 460-2. At time 460-3, the first column ofdata from the SRAM can be transferred to the activated row in DRAM. Asecond column of data can be read from the SRAM at time 460-4. At time460-5, the second column of data from SRAM can be transferred to theactivated row in DRAM. A third column of data can be read from SRAM at460-6. At time 460-7, the third column of data from the SRAM can betransferred to the activated row of DRAM. A fourth column of data can beread from SRAM at 460-8. At time 460-9, the fourth column of data fromSRAM can be transferred to the activated row of DRAM.

FIG. 4B is a schematic diagram illustrating circuitry for transferringdata from SRAM to DRAM in accordance with a number of embodiments of thepresent disclosure. The FIG. 4B schematic diagram can include a memoryarray 410 coupled to a cache 414 via data line (e.g., data path) 423.For ease of explanation and illustration of FIG. 4B, the memory array410 can be DRAM 410 and the cache 414 can be SRAM 414.

The DRAM 410 can include a number of rows 440-0, . . . , 440-W and anumber of columns 434-0, . . . , 434-Z and the SRAM 414 can include anumber of rows 450-0, . . . , 450-U and a number of columns 454-0, . . ., 454-V. The DRAM 410 can also include a number of sense amplifiers406-0, . . . , 406-Y. Memory cells can be located at the intersectionsof rows 440-0, . . . , 440-W and columns 434-0, . . . , 434-Z and at theintersections of rows 450-0, . . . , 450-U and columns 454-0, . . . ,454-V.

To transfer data from the SRAM 414 to the DRAM 410, one of the number ofrows 440, . . . , 440-W of DRAM 410 can be activated, one of the numberof rows 450-0, . . . , 450-U can be selected, data from one of thenumber of columns 454-0, . . . , 454-V in SRAM 414 can be read andlatched in one of the number of sense amplifiers 406-0, . . . , 406-Y,and the data can be transferred to one of the number of columns 434-0, .. . , 434-Z in the DRAM 410. For example, row 440-0 can be activated,row 450-1 can be selected, data from column 454-0 can be read,transmitted to the DRAM 410 via data line 423, and latched in senseamplifier 406-2, and the data can be transferred to column 434-2 in theDRAM 410. The data path for transferring data between DRAM and SRAM caninclude digit lines that transfer data from sense amplifiers 406-0, . .. , 406-Y to memory cells at intersections of rows and columns. The datapath for transferring data between DRAM and SRAM can include data line423 that can be coupled to sense amplifiers sense amplifiers 406-0, . .. , 406-Y via DRAM interface. Data line 423 can also be coupled to ashared I/O line (e.g., shared I/O line 222) to transfer data betweenDRAM and SRAM. The data path can also include data line 423 can becoupled to and/or be part of data line 447. Data lines 423 and 447 canbe coupled to the DRAM interface and SRAM interface, which can receivedata and/or commands on data lines 423 and 447 and transfer the dataand/or commands to components of the DRAM and SRAM.

Once a row is activated, data can be transferred column by column byactivating columns one by one. Transferring the data can includetransferring data to and/or from a memory cell coupled to the activatedrow and column, and repeating the process by activating additionalcolumns of the activated row (e.g., activating and transferring data toand/or from a first column, then a second column, then a third column,etc.).

FIG. 5 is a flow diagram of a method for transferring data from DRAM toSRAM in accordance with a number of embodiments of the presentdisclosure.

At block 570, the method can include activating a first portion of adynamic random access memory (DRAM). Activating the first portion of theDRAM can include activating a bank in the DRAM and/or a row in the DRAM.

At block 572, the method can include reading data from the first portionof the DRAM. The data can be read from the first portion of the DRAM inresponse to the DRAM receiving a command.

At block 574, the method can include latching the data from the firstportion of the DRAM in a first sense amplifier of one or more senseamplifiers. A data bus can couple the DRAM and the one or more senseamplifiers.

At block 576, the method can include transferring the data from thefirst sense amplifier to a first portion of a static random accessmemory (SRAM). The data bus can couple the one or more sense amplifiersand the SRAM. transferring the data from the one or more senseamplifiers to the first portion of the SRAM can include writing the datato a row of the SRAM. The SRAM can transfer the data from the one ormore sense amplifiers to the first portion of the SRAM in response toreceiving a DRAM command. The DRAM command can be from a DRAMcontroller. In some examples, the DRAM command can be converted to aSRAM command. The converted DRAM command can be executed to read and/orwrite data column by column on an activated row of the SRAM.

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art will appreciate that anarrangement calculated to achieve the same results can be substitutedfor the specific embodiments shown. This disclosure is intended to coveradaptations or variations of one or more embodiments of the presentdisclosure. It is to be understood that the above description has beenmade in an illustrative fashion, and not a restrictive one. Combinationof the above embodiments, and other embodiments not specificallydescribed herein will be apparent to those of skill in the art uponreviewing the above description. The scope of the one or moreembodiments of the present disclosure includes other applications inwhich the above structures and methods are used. Therefore, the scope ofone or more embodiments of the present disclosure should be determinedwith reference to the appended claims, along with the full range ofequivalents to which such claims are entitled.

In the foregoing Detailed Description, some features are groupedtogether in a single embodiment for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the disclosed embodiments of the presentdisclosure have to use more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thus,the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment.

What is claimed is:
 1. A method for performing a data transferoperation, comprising: receiving a command from a controller at adynamic random access memory (DRAM) via a data bus, wherein thecontroller and DRAM are coupled together via the data bus; activating afirst portion of the DRAM in response to the DRAM receiving the commandfrom the controller; reading data from the first portion of the DRAM;receiving a DRAM command from the DRAM at a static random access memory(SRAM); converting the DRAM command to an SRAM command; and writing thedata from the first portion of the DRAM to a first portion of the SRAMin response to the SRAM receiving the DRAM command from the DRAM.
 2. Themethod of claim 1, wherein activating the first portion of the DRAMcomprises: activating a bank in the DRAM; and activating a row in theDRAM; and a first column in the DRAM.
 3. The method of claim 1, whereinwriting the data from the first portion of the DRAM to the first portionof the SRAM comprises writing the data to a row of the SRAM.
 4. Themethod of claim 1, further comprising: receiving another command fromthe controller at the DRAM via the data bus; activating a second portionof the DRAM in response to the DRAM receiving the another command fromthe controller; receiving another DRAM command from the DRAM at the SRAMand converting the DRAM command to an SRAM command reading a secondportion of data from a second portion of the SRAM in response to theSRAM receiving the DRAM another command from the DRAM; and writing thesecond portion of data from the second portion of the SRAM to the secondportion of the DRAM in response to the DRAM receiving the anothercommand from the controller.
 5. The method of claim 4, whereinactivating the second portion of the DRAM includes activating a secondcolumn of the DRAM.
 6. The method of claim 1, further comprisingtransferring the first portion of data from the first portion of theDRAM to the first portion of the SRAM via a first data path.
 7. Amethod, comprising: receiving a command from a controller at a dynamicrandom access memory (DRAM) via a data bus, wherein the controller andthe DRAM are coupled together via the data bus; activating a firstportion of the DRAM in response to the DRAM receiving the command fromthe controller; receiving a DRAM command from the DRAM at a staticrandom access memory (SRAM); converting the DRAM command to an SRAMcommand; and reading a first portion of data from a first portion of theSRAM in response to the SRAM receiving the DRAM command from the DRAM;and writing the first portion of data from the first portion of SRAM tothe first portion of the DRAM in response to the DRAM receiving thecommand from the controller.
 8. The method of claim 7, whereinactivating the first portion of the DRAM comprises: activating a bank ofthe DRAM; and activating a row of the DRAM.
 9. The method of claim 7,wherein writing the first portion of data from the first portion of SRAMto the first portion of the DRAM comprises writing the data to a columnof the DRAM.
 10. The method of claim 7, further comprising: receivinganother command from the controller at the DRAM via the data bus;activating a second portion of the DRAM in response to the DRAMreceiving the another command from the controller; reading a secondportion of data from the second portion of the DRAM in response to theDRAM receiving the another command from the controller; receivinganother DRAM command from the DRAM at the SRAM and converting the DRAMcommand to an SRAM command; and writing the second portion of data fromthe second portion of the DRAM to a second portion of the SRAM inresponse to the SRAM receiving the another DRAM command from the DRAM.11. The method of claim 7, further comprising transferring the firstportion of data from the first portion of the SRAM to the first portionof the DRAM via a first data path.
 12. An apparatus, comprising: adynamic random access memory (DRAM) including one or more senseamplifiers; and a static random access memory (SRAM) coupled to the DRAMvia a data bus, wherein the apparatus includes a controller configuredto: send a command to the DRAM via the data bus, wherein the DRAM isconfigured to activate a DRAM row and read the data from the DRAM row inresponse to receiving the command from the controller; and wherein theSRAM is configured to receive a DRAM command from the DRAM, convert theDRAM command to an SRAM command, to write the data from the DRAM row toa SRAM row in response to receiving the DRAM command from the DRAM. 13.The apparatus of claim 12, wherein the SRAM comprises two ports andwherein the two ports are multiplexed.